Research from the Earlham Institute in Norwich, in partnership with the International Maize and Wheat Improvement Centre (CIMMYT), provides much-needed hope for enhancing crop resilience and food security in the face of climate change following a year in which temperature records have been broken.
The field tests in Mexico also highlight the value of genetic diversity in important crops, whose capacity to adapt to a rapidly warming planet has been diminished by decades of selective breeding.
As temperatures rise and weather events get more severe, there is growing uncertainty about the ability of major food crops to continue to meet global demand.
More calories are produced worldwide from wheat than from any other crop, but because there is little genetic diversity in the majority of wheat grown globally, it is particularly susceptible to the effects of climate change.
Wheat is responsible for around 20 per cent of the calories consumed globally and is widely grown all over the world. But we don’t know whether the crops we are planting today will be able to cope with tomorrow’s weather. To make matters worse, developing new varieties can take a decade or more so acting quickly is vital.”
Anthony Hall, Study Lead Author and Head, Plant Genomics, Earlham Institute
Researchers from the Earlham Institute established a two-year field trial in Mexico’s Sonora desert in cooperation with CIMMYT. They looked at 149 wheat varieties, ranging from elite lines that are widely grown to landraces from Mexico and India that were selectively bred to contain DNA from wild relatives.
Crossing elite lines with exotic material has its challenges. There is a well-recognized risk of bringing in more undesirable than desirable traits, so this result represents a significant breakthrough in overcoming that barrier and the continued utilization of genetic resources to boost climate resilience.”
Matthew Reynolds, Study Co-Author and Leader, Wheat Physiology, International Maize and Wheat Improvement Centre
The crops were subjected to the type of heat stress that is anticipated to become the norm as global temperatures rise because the seeds were planted later in the growing season to force the plants to grow during warmer months.
They discovered that plants bred with exotic DNA produced 50% more wheat than wheat without this DNA. Importantly, under typical circumstances, neither the exotic nor the elite lines performed worse.
To identify the precise genetic variations causing the increased heat tolerance, the researchers sequenced the plants. They discovered genetic markers that might enable the selective introduction of this advantageous exotic DNA into elite lines, providing an expedient means of enhancing climate resilience and reducing the risk of widespread crop failures.
As we try to produce more food from less land to feed a growing global population, we urgently need to future-proof the crops we are planting so they can thrive in an increasingly hostile climate. The key to this, we are increasingly finding, may lie within largely untapped genetic resources from wheat’s wild relatives and landraces.”
Benedict Coombes, Study Lead Author and PhD Student, Earlham Institute
The researchers recommend incorporating heat tolerance traits into breeding programs as a preventative measure to create wheat crops that can withstand less predictable weather.
Hall added, “This is science we can now use to make an impact almost immediately. We’ve done the field trials, we know what genetic markers we are looking for, and we are starting conversations with wheat breeders so this is hopefully going to be the first of many steps to contribute to global food security in the coming years. The discoveries we are making, and the action we are taking, will hopefully mean people around the world can continue to have nutritious food on their plates.”
Molero, G., et al. (2022). Exotic alleles contribute to heat tolerance in wheat under field conditions. Communications Biology. doi.org/10.1038/s42003-022-04325-5